Conventionally, rotation friction torques of opening/closing shafts and rotation shafts of two-shaft hinges are generated in most cases by mechanisms employing structures of a plate member wrapping around a shaft or structures of a pressed disc spring.
FIG. 16 shows an example of a conventional two-shaft hinge. A plate spring 54 formed into a wave-like shape and a bracket 56 are fixed onto each side of a supporting plate 52 of a pressed opening/closing shaft by means of a fixing flange 53. A rotation shaft 57 pierces through the supporting plate 52 of the opening/closing shaft at the center thereof. A rotational torque is provided by friction of a pressed plate spring 59.
In the conventional hinge, a rotating angle stopper mechanism is not provided, and thus a torque is generated by pressing a friction plate that uses the repulsive force of a disc spring. This leads to problems such as wear of the supporting plate 52 and the bracket 56, free-play and looseness due to deformation of the plate spring 54, and low mechanical durability. The fluctuation in torque or deterioration of durability in time causes degrading of the quality and a breakdown of the device. In the latest two-shaft hinges, compared to the conventional hinges, the operability and feelings in opening/closing and rotating are required, and thus a mechanism for limiting the rotating angle and opening/closing angle and a stable torque value, high durability, and reduction in size and weight are strongly demanded.